1. Preheat the oven to 220C/425F
2. Put the flour, salt, sugar and baking powder into a food processor, then add in the butter, and process until the mixture looks like fine breadcrumbs. Tip into a large bowl, then make a well in the middle.
3. Warm the yoghurt, milk and vanilla together in a pan
4. Tip the warm yoghurt mixture into the bowl and quickly work into the flour mix with your hands
5. Tip the dough onto a floured surface and without handling the dough too much bring it together to form a smooth dough
6. Roll the dough out to 1 ½ inch thick and cut out 9 rounds with a pastry cutter. Squash any remaining dough lightly together, and then repeat until the dough is used up.
7. Place onto a baking tray lined with greaseproof paper
8. Brush the tops with egg wash and bake for 12 minutes until risen and golden.

Chef tip

These scones are best eaten just-warm, or on the day of making